EE8702 POWER SYSTEM OPERATION AND CONTROL /MODEL NOV 2020

1.1 Objectives of power system is/are

• a. Cost of electrical energy per KWh is to be minimum

• b. Rated voltage and frequency has to be supplied to the consumers

• c. both a and b

• d .neither a nor b

1.2 The frequency of the power system control the

• a. Active power

• b. Reactive power

• c. (a) and (b) both

• d. None of them

1. 3 The value of diversity factor is ............. than 1

• a. equal to

• b. lesser

• c. more

• d. greater

1. 4 Area under the daily load curve divided by 24 gives..............

• a. average load

• b. maximum demand

• c. units generated

  
  

• d. load factor

1.5 What is a load factor?

• a. The ratio of average to maximum demand.

• b. The ratio of maximum demand to average load.

• c. The product of maximum demand and average load.

• d. The ratio of average load to the plant capacity.

  
  

1.6 The heart of the speed governor system, which controls the change in speed, is

• a. Linkage mechanism.

  
  

• b. Fly-ball speed governor.

• c. Speed changer.

• d. Hydraulic amplifier.

1.7 (2 marks)

When two identical AC-generating units are operated in parallel on governor control, and one machine has a 5% governor droop and the other a 10% droop, the machine with the greater governor droop will

• a. Tend to take the greater portion of the load changes.

• b. Share the load equally with the other machine.

• c. Tend to take the lesser portion of the load changes.

• d. None.

1.8 ( 2 marks) A thermal generating station has a installed capacity of 15 MW and supplies a daily load of 10 MW for 12 hours and 5 MW for remaining 12 hours. The plant capacity factor for this station is

• a. 1

• b. 0.75

• c. 0.67

• d. 0.5

1.9 ( 2 marks) More efficient plants are used as

• a. Base load plant

• b. Peak load plant

• c. Both 1 and 2

• d. Non of the above

2.1 main control loops in generating stations are:

• a. ALFC.

• b. AVR.

• c. Both (a) and (b).

• d. None of these.